I am looking to make a Mac version of one of my iPhone apps and was looking for a good ay to hit the ground running. I know how to code in Objective-c and Cocoa, and I know how to piece something together from scratch if I have to, but I am looking for an easier way.

Are there any open-source templates for coding Mac desktop applications that I might be able to pick up and use to get started off without reinventing the wheel?

EDIT:

I guess what I am looking for is an easy way to get started on an app that has the "iTunes Look and Feel". If there are some bare-bones version of this layout as some sort of template project, that would be great. Also, why has somebody down-voted this question? Have I asked something that is not appropriate for SO?

Apple includes lots of project templates with Xcode (vanilla application, document-based application, Core Data document-based application, etc.). I don't really know how much more you would want in a template. They're generally pretty good for getting you started, I think. If you're looking for something more than these offer out of a "template," maybe you could elaborate.

Besides the project templates included with Xcode, you should browse the application exmples in /Developer/Examples. Most of these examples are "full" applications that demonstrate one or more Cocoa-related concepts. Many could serve as the starting point for a similarly orriented app of your own.